Add details of the new hv-gpci interface file called
"processor_bus_topology" in the ABI documentation.
Reviewed-by: Athira Rajeev <[email protected]>
Signed-off-by: Kajol Jain <[email protected]>
---
.../sysfs-bus-event_source-devices-hv_gpci | 32 +++++++++++++++++++
1 file changed, 32 insertions(+)
diff --git a/Documentation/ABI/testing/sysfs-bus-event_source-devices-hv_gpci b/Documentation/ABI/testing/sysfs-bus-event_source-devices-hv_gpci
index 12e2bf92783f..ba3f9aa3d68e 100644
--- a/Documentation/ABI/testing/sysfs-bus-event_source-devices-hv_gpci
+++ b/Documentation/ABI/testing/sysfs-bus-event_source-devices-hv_gpci
@@ -80,3 +80,35 @@ Contact: Linux on PowerPC Developer List <[email protected]>
Description: read only
This sysfs file exposes the cpumask which is designated to make
HCALLs to retrieve hv-gpci pmu event counter data.
+
+What: /sys/devices/hv_gpci/interface/processor_bus_topology
+Date: July 2023
+Contact: Linux on PowerPC Developer List <[email protected]>
+Description: admin read only
+ This sysfs file exposes the system topology information by making HCALL
+ H_GET_PERF_COUNTER_INFO. The HCALL is made with counter request value
+ PROCESSOR_BUS_TOPOLOGY(0xD0).
+
+ * This sysfs file will be created only for power10 and above platforms.
+
+ * User needs root privileges to read data from this sysfs file.
+
+ * This sysfs file will be created, only when the HCALL returns "H_SUCCESS",
+ "H_AUTHORITY" or "H_PARAMETER" as the return type.
+
+ HCALL with return error type "H_AUTHORITY" can be resolved during
+ runtime by setting "Enable Performance Information Collection" option.
+
+ * The end user reading this sysfs file must decode the content as per
+ underlying platform/firmware.
+
+ Possible error codes while reading this sysfs file:
+
+ * "-EPERM" : Partition is not permitted to retrieve performance information,
+ required to set "Enable Performance Information Collection" option.
+
+ * "-EIO" : Can't retrieve system information because of invalid buffer length/invalid address
+ or because of some hardware error. Refer to getPerfCountInfo documentation for
+ more information.
+
+ * "-EFBIG" : System information exceeds PAGE_SIZE.
--
2.39.3